Process for the manufacture of compressed yeast



Patented Mar. 20, 1923.

UNITED STATES 1,449,103 PATENT OFFICE.

FRIEDRICH HAYDUCK, OF WILMERSDORF, GERMANY, ASSIGNOR TO THE FLEISCH-MANN COMPANY. OF NEW YORK, N. Y., A CORPORATION OF OHIO.

PROCESS FOR THE MANUFACTURE OF COMPRESSED YEAST.

Ho Drawing.

Application filed October 30, 1820. Serial No. 420,830.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L,1313.)

To all whom it may concern:

Be it known that I, FRIEDRICH HAYDUCK, a citizen of Germany, residing atWilmersdorf, Germany, have invented certain new and useful Improvementsin Processes for the Manufacture of Compressed Y east and the Product(for which ap lication for patent was filed as follows, ermany', March15, 1915, Patent No. 303,251), of which the following is aspecification.

This invention relates to a process for the manufacture of yeast,particularly bakers yeast, by propagation in a solution containlng sugarmaterial and yeast nourishing inorganic salts.

An object of this invention is to provide a procedure for themanufacture of yeast on a large scale commercially, there being added tothe nutrient solution which contains sugar material and yeast nourishinginorganic salts a neutralizing agent for neutralizing the deleteriousexcess of acidity.

Another object is to provide a good bakers yeast in a convenient andeconomical manner.

In the production of yeast in accordance with the process described inGerman Patent No. 300,663, and in my corresponding copending applicationfor United States Pat-- ent Serial No. 420,829, filed October 30, 1920,there takes place in solutions of sugar and inorganic salts, even whenno bacterial infection sets in, a considerable increase in the acidcontent of the nutrient solution in which the yeast is produced. Theresultant acidity is, for the most part, of an inorganic nature, andsuch inorganic acid is released from the inorganic salts used, the basicparts are used to a large extent as nutriment by the yeast, while theresidual acid parts remain. This selective partial utilization by theyeast of components of inorganic salts present tends to result in anaccumulation of acid products or free inorganic acids and tendsincreasingly to acidify the solution in which the yeast is beingpropagated or grown. Because of the presence of these ree acids, theyeast, as can be seen by examination of the same with a microscope, isinfluenced unfavorably if the acids exert their action unrestrainedlyupon the yeast for any considerable length of time.

I have now discovered that unexpectedly high yeast yields are obtainedwhen conducting the nutrition of the yeast with the use of solutionscontaining sugar and yeastnutrient inorganic salts in accordance with aprocess of the character exemplified in my aforementioned copendingaapplication Serial Number 420,829, if the aci components referred to asbein set free during the yeast propagation am? growth are neutralizedeither entirely orto such an extent that they no longer afl'ect theyeast unfavorably. For such neutralization of the acid com nents,calcium carbonate may suitably employed, but other basic or antacidsubstances such as antacid substances containing or supplying nitrogencan also be employed for the neutralization, for example ammoniumcarbonate.

A suitable yeast-nutrient solution for the propagation of yeastaccording to the method of my present invention may be formed as followsand as described in my aforesaid co-pending application Serial No.420,829: 100 parts of sugar are dissolved in tap water together with 6parts ammonium su fate, 2 arts ammonium dihydrogenphosphate (NI LH POJ,4 parts potassium sulfate, 2?, parts of gypsum and 22; parts magnesiumsulfate and the solution is made up to a total quantity of 6500 to 7000parts with'the requisite quantity of water, (all' parts being stated byweight).

The process of my present invention may be executed in such manner, forexample that calcium carbonate is added to the nutrient solution eitherat the beginning or fractionally during the process, to an amountcorresponding to the sulfuric acid contained in and which may be setfree from the ammonium sulfate used in the yeast growing process in caseammonium sulfate is employed as one of the principal inorganicyeast-nutrient salts. In the case of such employment of ammoniumsulfate, in accordance with the molecular weight of the compoundsinvolved, there may be suitably employed for every 10 parts by weight ofammonium sulfate (since the yeast tends to utilize for its nutrition thetotal basic part of this salt) up to 7 arts by weight of calciumcarbonate. 0 asses may be used in my process as a suitable source ofsugar for the yeast production and if molasses naturally containingantacid substances is.

used as the sugar-containing raw material the uantity of calciumcarbonate employed can e reduced materially, as the antacid substancespresent in such molasses neutralize a part of. the free acid. Whethercalcium carbonate or an antacid nitrogensupplying substance or otherneutralizing agent be used it will, of course, be employed in suchamount as to neutralize whatever detrimental excess of free acid tendsto develop in the nutrient medium during the yeast growth and asstatedabove it may be added fractionally in successive ortions.

The technical advantages of my I improved process hereinafter claimedcan be seen from the following:

While in a process as described in my above-mentioned copendinapplication for United States Patent No. 0,829, from 100 kilograms ofsugar employed in the yeastnutrlent solution not more than about from 70to 80 kilograms of compressed bakers yeast ,is ordinarily obtained,there can be obtained when making use of the method includingneutralization in accordance with the process of this resentapplication, up to 160 kilograms 0F bakers yeast from a nutrientsolution containing 100 kilograms of sugar and if there is used a quickgrowing species of yeast, up to 300 kilograms of compressed yeast can beobtained from such a nutrient solution containing 100 kilograms ofsugar, that is, therefore, from two 35, to four times the yield obtainedin the heretofore usual process employing cereal wort for themanufacture of yeast by the aeration method, calculated on the starch oravailable carbohydrate content of the raw r the a patent materials, andup to approximately twice yield, similarly calculated, ObtMIlBd by myimproved process as set forth in 111 ccpendin ap lication for' Unitedtates ria Number 420,829. g The neutralization of acids may, also beadvantageous in processes involving the fermentation of pure sugarsolutions in the presence of inorganic salts in certain instances evenwhen the obtainment of yeast is not intended.

It is known that there can be added to meshes in lactic fermentation,nitrogen-sup 'plying antacid substances, as for instance ammonia,ammonium carbonate or ammonium carbamate, for the partial neutralizationof-tlie lactic acid progressively formed and for the augmentation of theyeast-assimilable nitrogen content of the mashes so that they may beutilized for subsequent yeast p ro a ation.

It is al o nown that an addition ofrbasic or antacid substances to somefermenting liquids stimulates the fermentation, the injurious action ofthe acids on the life of the yeast being inhibited. Furthermore,therehas already been some theoretical discussion with respect to thepossibility of obtaining yeast on an industrial scale from solutionscontaining sugar and inorganic salts. A practical embodiment of such aprocess, based upon my discoveries, is described in and broadly claimedin my copendin apglication for United States patent er. 0. 420,829hereinabove referred to. An outstanding novel and technically importantfeature of my present invention as compared with the process describedand claimed in my afonesaid copending application Serial No. 420,829resides in the fact that by means of the careful neutralization of theaforesaid acid com onents set free are neutralized either entire y or toan extent that they no longer afl'ectgthe yeast unfavorably wherebyyeast yields may be obtained which have not been obtainable hitherto byan process and which could not have been pre icted from the known facts.

While in the foregoing descri tion I have given a detailed embodiment ofmy present invention, it will, of course, be apparent that the inventionis not li-mited to the use of the particular substances employed asyeast nutrients but that my resent invention is merely typified andillustrated by the example given and includes broadly all such processesas come within the scope of the claims hereinafter presented, bearing inmind the fact that substances such as fermentable sugars, added as suchor in the form of molasses, and suitable yeast-nutrient salts as tyified by those in the example given will be used, in accordance with myprocess and claims, in such aggregate quantities and in such proportionsas are requisite for supplying 1n the proper'proportions and inyeast-assimilable form or combination the necessary carbon, nitrogen,phosphorus and other essential yeast-constituent elements for theproduction of yeast in such quantities as are desired and referably inthe high yield hereinabove indicated as chtainab' e by the process of myresent invention, when carried out withisuitable aeration of thenutrient solution during the yeast production. It is known that thefermenting power and other desirable characteristics of yeast are to acertain degree dependent upon a sufficiency, in the nutrient solution inwhich the yeast is produced, of nitrogen-supplying substances and in thepractice of my present invention such a quantity of ammonium salts andother substances will of course be ordinarily employed as will produce acompressed yeast having the well-known desirableanitrogen content andproperties. i

As is stated in my German Patent No. 390,663 and in my corresponding aplication for United States patent Seria No. 420,829, specially goodresults with respect aeration, said a propagation, and during to theobtainment of high yields of yeast from nutrients of the types involvedin the present application may besecured by employment of nutrientsolutions which have a density of not more than 2 on the saccharometer.

Having described ,my invention, what I claim as new and desire to secureby Letters Patent is 1. The process of manufacturing yeast whichcomprises preparingm yeast nutrient solution and ropagating yeastthereinwith aeration, sai yeast nutrient solution containin essentially sugarmaterial and yeast nouris ing inorganic salts from which comonents areliberated which tend increasingy to acidify the nutrient the period ofpropagation neutralizing the deleterious excessof such acid ity.

2. The process of manufacturing yeast which comprises preparing a yeastnutrient solution and propagating yeast therein with aeration, saidyeast nurtient solution containin essentially sugar material and yeastnouris ing'inorganic salts from which components are liberated whichtend increasingly to acidify the nutrient solution during propagation,and during the period of propagation neutralizing the deleterious excessof such acidity by the addition of an innocuous antacid substance. v

3. The process ofmanufacturing yeast which comprises preparinga yeastnutrient solution and propagating yeast therein with aeration, saidyeast nutrient solution o0ntaining essentially sugar material and yeastnourishing inorganic salts from which components are liberated whichtend increasingly to acidify the nutrient solution during propagation,and during the period of rop agation neutralizin the deleterious excessof such acidity by tfi e fractional addition of an innocuous antacidsubstance.

4. The process of manufacturing yeast comprises preparing a yeastnutrient solution and propagating yeast therein with yeast nutrientsolution-containin essentially sugar material and yeast nouris iinginorganic salts from which components are liberated which tendincreasing- 1y to acidify the nutrient solution during propagation, andduring the period of propagation neutralizing the deleterious excess ofsuch acidity. by the addition of an innocuous antacid substance adaptedto supply yeast assimilable nitrogen to the yeast.

5. The process of manufacturing yeast which comprises preparing a yeastnutrient solution and (propagating yeast therein with aeration, saiyeast" nutrient solution containing essentially sugar'material and yeastnourishing inorganic salts from which components are liberated whichtend increasingly to acidify the nutrient solution during solutionduring propagation, and durin the agation neutralizin 0 such acidity byt uous carbonate.

6. The process of which comprises Iperiod of propt e de eterious excesse addition of an innocmanufacturing yeast preparing a yeast nutrientponents are li'ber ated which tend increasing ly to acidify the nutrientsolution during propagation, and during the period of propagationneutralizing the deleterious excess of such acidity carbonate.

7. The prooes which comprises solution and aeration, sai

by the addition of ammonium i;

s of manufacturing yeast preparing a yeast nutrient taining essentiallysugar material and yeast nourishing inorganic salts including a compoundcontaining which is adapted yeast and from which dursimilated by the ingsuch assimilation comp erated which te the nutrient sol and during theperiod of tralizing the deleterious acidity. 8. he proces whichcomprises solution and (p aeration, sai

yeast assimilable nitrogen to be at least partially asonents are libndincreasingly to acidify u'tion during propagation,

propagation neus of manufacturing yeast preparing a yeast nutrientropagating yeast therein with yeast nutrient solution 'con tainingessentially sugar material and yeast nourishing inorganic saltsincluding an inorganic ammoniacal compound adapted to supply at least amaterial portion of yeast assimilable nitrogen re during propagation,said uired by the yeast salts being of a character such that componentsare liberated which tend increasingly to acidify the nutrient solutionduring propagation, and during the period of propagation neutralizingthe deleterious excess of such acidity.

9. The proces which comprises s of manufacturing yeast preparing a yeastnutrient solution and propagating yeast therein with aeration, saidyeast taming essentially sugar material and yeast nourishing inorganicsalts nium sulphate which is least partially assimilated from whichduring such including ammoadapted to be at by the yeast and assimilationcomnutrient solution con- 1 ropagating yeast therein with yeast nutrientsolution conexcess of such ponents are liberated which tend increasinglyto acidify the nutrient solution during propagation, and during theperiod of propagation neutralizing the deleterious excess of ac'dity.

10. The process of manufacturing bakers yeast which comprises preparinga yeast nutrient solution and propagating yeastfl therein with aeration,being of a dilu said yeast nutrient solution tion corresponding to notmore than 2 on the saccharoineter and containing essentially sugarmaterial and yeast nourishing inorganic salts from which components areliberated which tend increasingly to acidify the nutrient solutionduring propagation, and during the period of propagation neutralizingthe deleterious excess of such acidity by the fractional addi' tion ofan innocuous antacid compound.

12. The process of manufacturing yeast which comprises preparing a yeastnutrient solution and propagating yeast therein with aeration, saidyeast nutrient solution containing essentially molasses and yeastnourishing inorganic salts from which components are liberated whichtend increasingly to acidify the nutrient solution during, propagation,and during the period of propagation neutralizing the deleterious excessof such acidity.

13. The process of manufacturing yeast which comprises preparing a yeastnutrient solution and propagating yeast therein with aeration, saidyeast nutrient solution containingessentially molasses and yeastnourishing inorganic salts including a compound containin yeastassimilable nitrogen which 40 is adapte to be at least partiallyassimilated by the yeast and from which during such assimilationcomponents are liberated which tend increasingly to acidify the nutrientsolution, and during the period of propagatrient solution andpropagating yeast therein with aeration, said yeast nutrient-solutionconsisting essentially of molasses and yeast 'nourishing inorganic saltsfrom which components are liberated which tend increasing ly to 'acidifythe yeast nutrient solution during propagation, and during the period ofpropagation neutralizing the deleterious excess of acidity by theaddition of an innocuous antacid compound.

15. As an article of manufacture, a yeast product adapted for bakingpurposes, of which substantially all of the principal constituents havebeen assimilated during propagation in a nutrient solution consisting ofessentially sugar material and yeast nourishing inorganic salts fromwhichcomponents are released tending increasingly to acidify thenutrient solution during propagation, the deleterious excess ofsuchacidity being neutralized during the period of 7 propagation by theaddition of an innocuous antacid substance.

In testimony whereof, I have aflixed my signature.

FRIEDRICH HAYDUC'K.

4 t that in Letters Patel 1t Neil, r

of Fri'edrich Haydukfiof Wi n orfi,

' with those oon'atidn's' themin that thg same may p cmm m orcb tion;

' tedMu-ch 20 1 upon the application I pn' provemont m P for theManufactum (if Compressed Yeast, errors tppear-in the printqdSecificat-io'n re'quiring correction as followsz-Paga '1, line 44; afterth word. aci 's. insert the word in; 'pa. 3, 'lineif, 2, for the wordnurtient read nutrient,- and that the aid fitters Pa nt should be onformto the moor-c1 of the cum in th Pafentofica. 'Signgd ind this 19th dayof June, A. D., 192}. i

{ml-5 a Germany, fOI

